84 ANNUAL OF SCIENTIFIC DISCOVERT. 



ing armor below the water line. He illustrated the penetrative 

 power of long projectiles, -with the flat front lired at extreme 

 angles agahist iron plates, by the projectiles actually fired and 

 the plates they penetrated. The gun from which all the projec- 

 tiles were lired was a o-pounder; it weighs 315 lbs., and the 

 maximum diameter of its bore is 1.85 inches. The charge of 

 powder used was 10 ounces, and the weight of the G-iuch diam- 

 eter ])rqjcctilcs is G 11)S. lie considered he had established the 

 sui)eriority of the llat-iVontcil projectiles made of his metal, and 

 that the Palliser jirojeotiles fail to penetrate when striking at an 

 angle, solely on account of the form of the head. The results 

 obtained with the small calibre of the riile closely agree with 

 those of the ;5-pounder gun. He had always found that what he 

 could do with the smaller calibres could be reproduced in the 

 larger sizes, and could be repeated on a proportionate scab' with 

 his y-inch gun, or the 11-inch guns his firm are now engaged in 

 constructing. The 9-ineh guns weigh 15 tons each, and are 

 capable of firing powder charges of 50 lbs. A 9-inch armor 

 shell, 5 diameters long, weighs ij:)0 lbs., and will contain a burst- 

 ing charge of 25 lbs. These projectiles would pierce the side of 

 a ship plated with armor at a distance of 2,000 yards, and at 

 some depth behnv the water line. The 11-inch guns will weigh 

 27 tons, and will be capable of firing 90 lbs. powder charges. 

 The 11-inch shells, 5 diameters long, will weigh 9G5 lbs., and 

 will contain bursting charges of 45 11 )S., and would i)ierce a side 

 of the ship " Hercules," plated with 9-inch armor, at a distance 

 of 2,000 yards. He had named these long projectiles the " anti- 

 war" shell. Four guns of 12 inches bore have lately been put on 

 board the "Monarch;" they weigh 25 tons each, and fire charges 

 of 50 lbs. and G7 lbs., and projectiles of GOO lbs. weight; Init the 

 weight of these guns was in proportion to their bore ; and if the 

 material were the best that could be supplied, they ought to fire 

 117 lbs. of powder and projectiles 1,450 lbs. weight. 



LIFE OF AMERICAN VESSELS. 



At the meeting of the American Association, at Salem, Profes- 

 sor E. B. Elliott, of Washington, gave a Life Table of American 

 Sea-Going Sailing Vessels, derived from the career of 20,7o7 ves- 

 sels, of which l,i()5 were known to be extant. The tabic shows 

 that out of 1,U00 vessels 581.4 survive 10 years, 219.5 20 years, 

 67.2 30 years, 11.1 40 years, and none 50 years. Tiie average 

 dm*ation of ships is 13.8 years; of those which have been built 

 10 years, 9.3 years longer; built 20 years, 7.2; 30 years, G.2; 40 

 yetirs, 2.7. 



I'rofessor Pierce expressed his interest in the paper, and a 

 desire that a similar table might be made for English vessels, to 

 see if the superior education of British sea-captains would be 

 evinced. 



Professor Elliott also gave the values of the standard .Monetary 

 Units in which United SUites securities are quoted in the com- 



i 



